Should I intentionally magnetize my watch

I would not recommend it.  Given the parachrom hairspring and other metallurgy properties, Rolex watches from that era up are fairly resistant to magnetic fields. Doing so would require a significant magnet which will likely do more harm than good.

Hate to say it, sounds like it is due for a service. You may be able to get a local maker to regulate it.

I do not believe I would at all. I’d have it serviced.

You think it be a good idea to intentionally magnetize it so it runs faster? 

That's kinda like turning the radio up to fix the nagging squeal coming from the brakes.

um...............................no........that's not a very good idea at all.

-10 isn't something I would even notice

Not a watchmaker, but that seems like a bad idea.

Only if you intend to do that through natural means... like a thunderstorm.

 

(please don't tell me I have to spell out this is clearly NOT what anyone should do)

Service time, my friend.  When was the last time you sent it in?

I hope that was meant as a joke...

With potentially 17 years without a service, -10 spd doesn't surprise me. If you don't know the service history but have access to a timegrapher, the amplitude may very well be low if it hasn't been serviced. 

Good time to sell it and buy a watch from another brand. 

Absolutely not, you can try regulating the watch but agree with the many comments to service the watch.

This sounds like the chaotic-neutral method of watch servicing

Only if it is a Milgauss.  Honestly, take it in to be serviced.

Or don't worry about -10 seconds? There are bigger things to worry about!

👎👎👎

Sounds like it needs a first stage servicing including regulation.

Don’t be “cheap”. 

There's a very simple fix that will get you 100% accurate.

Step 1. Get a very strong neodymium magnet from eBay or AliExpress. It must be n35 or higher. 

Step 2. Clean the watch well with water and a fine tooth brush. 

Step 3. Sell the watch and get a quartz instead. 

It was sent back to serviced like 2 times in the last few months and the time is still off.

I already had it serviced twice in the last month and they made it -10 seconds.

Was running +45 seconds at first before I sent it in. 

Now it's running -10 seconds.

It's a Rolex, I wish it was built well like Omegas.  I never had this type of issues with any of my Omega, but both my Tudor and Rolex had this issue.

Anyone that says Rolex is same quality as Omega doesn't know much about watches.

Omega is a far superior built watch.  But Rolex has that prestigious marketing/reputation.