If it got stuck and there was any friction - it could easily melt the mono-filiment so it's not the same as just pulling out a stuck thread.
Products that could disolve the plastic could damage the finish on the machine, so you may want to remove the bobbin winding assembly before trying them. Possibly carb cleaner, but that will damage the finish. And you would need to get the chlorinated type, the non-chlorinated product will not. DH is racking his brain - stuff he knows would work is only available if you have a license to handle it as it is dangerous to your health to use.
And one more option - buy one off eBay and replace it. Probably cheaper than taking it to a shop.
Last edited by Macybaby; 11-03-2013 at 02:23 PM.