Reddit mentions of GC Waldom Degaussing Coil, 9317, For Color CRT, Hi Power

you degaussed the screen. there are products out there specifically made for that purpose

https://www.amazon.com/Waldom-Degaussing-Coil-Color-Power/dp/B00011UYJU

Looks like a Degaussing Coil for older CRT monitors.

You need a degaussing coil as what you described is most certainly what happened.

https://www.amazon.com/Waldom-Degaussing-Coil-Color-Power/dp/B00011UYJU

I haven't had to degauss anything in quite a while but of the two demagnetizers I keep in the shop one looks like an electronic engraver or a drill but with a thick wide tip instead of a pointed one and the other one looks like link 2 but oval shaped. You want the first one, the other is normally for tvs and hard drives

https://www.amazon.com/Universal-DEMAGNETIZER-Cassette-Recorder-Track/dp/B003ZKLP4W/ref=mp_s_a_1_3?keywords=demagnetizer&qid=1573084575&sprefix=demagnet&sr=8-3

https://www.amazon.com/Waldom-Degaussing-Coil-Color-Power/dp/B00011UYJU/ref=mp_s_a_1_8?keywords=degausser&qid=1573084679&sprefix=degau&sr=8-8

You will probably want to get a degausing coil and move the speakers away.

https://smile.amazon.com/Waldom-Degaussing-Coil-Color-Power/dp/B00011UYJU?sa-no-redirect=1

THere are youtube videos on how ot use it, if the built in degause button is fixing it temporarily, then you may need to use one of those.

Yes, it abolutely is a CRT degausser. They are indeed very often coil shaped. Like this one which you can still buy:

https://www.amazon.com/Waldom-Degaussing-Coil-Color-Power/dp/B00011UYJU

Bulk tape erasers are generally not coil shaped. As you can see:

https://www.google.com/search?q=bulk+tape+eraser

I still have a deguassing coil not at all sure what to do with it.