My charity shop special and bought for pennies Canon EOS 500 was found to have a sticky shutter after shooting my first film with it...
This one:
I did the traditional shutter repair using fag lighter petrol (naptha) and cotton buds...
I shot a second roll of film, a lot of it during our April Adventure to Norfolk, and keen to see if my shutter work had been successful I got busy in my bathroom cum darkroom...
Note that the tube of toothpaste was not used in the development process

And the result certainly seems to suggest my work was successful

Now to get back to fixing my duff Pentax now I have the required adhesive to repair the broken viewfinder eyepiece.