Do you demagnetize your watches?

I’ve had a seiko become magnetized, and it was very obvious: it ran super-fast. (I had foolishly stuck one of those powerful neodymium magnets in a spot where I could inadvertently bring my watch close to it.).  I’ve since moved the offending magnet and demagnetized the watch and all has been well.  I don’t have a routine for demagnetizing watches that are running well.  In this case it wasn’t feasible to stop the watch, but I’m not sure that would be helpful anyway.

@Joe_watchtime Thanks for posting this topic. I recently noticed (via Lepsi app) that 2 of my watches were magnetised and was looking around for a reliable demagnetiser. Now that this has happened, for myself, I am a little more conscious about placing/wearing watches near stuff that have magnets or produces magnetic fields (still trying to figure out safe vs. hazardous stuff). Just cautious, but not to the extend of being worried (should I be?). 

And yes, for those watches that are magnetised. I do plan to demagnetise them. Currently looking for a reliable demagnetiser. 

I have seen this one in videos etc.   Seems to do the trick based on reviews

https://www.amazon.com/Professional-Demagnetizer-Screwdriver-Tweezers-Mechanical/dp/B0874K9X25/ref=sr_1_2?crid=2LO9DFAMFDJLZ&keywords=demagnizer&qid=1655052583&sprefix=demagni%2Caps%2C112&sr=8-2

I had a Seiko 5 that ran super-fast (+15 seconds per minute) and I assumed I had magnetized it. Not having a compass nearby to test it (and not realizing that I could use the lepsi app as suggested by @Unholy), I was about to order a cheap de-magnetizer online when I decided to do a Google search on any other way to test whether the Seiko was magnetized.

According to the internet, Seikos running way too fast can be caused by a caught mainspring AND can be fixed like my old square tube television. One good whack on the caseback apparently freed up the mainspring and fixed mine saving me $20 on a cheap demagnetizer.  

This was the bit of wisdom/ "can't believe it worked" advice from Google: "If you [sic] watch is still running fast or slow by a large margin the most likely cause is that the mainspring may have gotten itself caught. To get it freed up try this: Place the watch on your palm with the crystal down and slap the watch. If this freed up the mainspring it should start keeping good time." https://www.citywatches.co.uk/articles/seiko-automatic-watches-troubleshooting/#:~:text=If%20you%20watch%20is%20still,should%20start%20keeping%20good%20time.

I don't know if I would try this on my more expensive watches (or if they have the same tendency to get caught mainsprings) but it worked after 2 tries with my beloved Seiko 5 a month ago and it's been good ever since. 
 

I had a Seiko 5 that ran super-fast (+15 seconds per minute) and I assumed I had magnetized it. Not having a compass nearby to test it (and not realizing that I could use the lepsi app as suggested by @Unholy), I was about to order a cheap de-magnetizer online when I decided to do a Google search on any other way to test whether the Seiko was magnetized.

According to the internet, Seikos running way too fast can be caused by a caught mainspring AND can be fixed like my old square tube television. One good whack on the caseback apparently freed up the mainspring and fixed mine saving me $20 on a cheap demagnetizer.  

This was the bit of wisdom/ "can't believe it worked" advice from Google: "If you [sic] watch is still running fast or slow by a large margin the most likely cause is that the mainspring may have gotten itself caught. To get it freed up try this: Place the watch on your palm with the crystal down and slap the watch. If this freed up the mainspring it should start keeping good time." https://www.citywatches.co.uk/articles/seiko-automatic-watches-troubleshooting/#:~:text=If%20you%20watch%20is%20still,should%20start%20keeping%20good%20time.

I don't know if I would try this on my more expensive watches (or if they have the same tendency to get caught mainsprings) but it worked after 2 tries with my beloved Seiko 5 a month ago and it's been good ever since. 
 

For most ordinary everyday life environments I would not be overly concerned. You generally will not be exposed to electromagnetic fields of more then a couple of watts, and will not be powerful enough to cause any harm.

Also most modern watch movements use magnetic resistant hairsprings and will often have a symbol that looks like the letter U with a line above it. The Seiko 4R movement is rated up to about 60 Gauss or about the power a couple of refrigerator magnets.

With that said I would avoid high power electronics such as audio equipment or powerful magnets like those used in loudspeakers unless you have something like a modern Omega that can withstand up to 15000 Gauss.

If you have access to or own a demagnetizer it is not a bad idea to give it a hit now and then but you should stop the movement when you do since direction of motion is important. So no spinny bits.