Actually this is not on a boat, but same principles will apply.

I need to reglue--with epoxy I hope--something that appears to have been
glued with silicone. I recall reading of a solution that could be used to
wash the silicone residue that would otherwise prevent good adhesion. Maybe
powdered detergent and kerosene ? Sounds messy, but my memory might be in
left field.

Any ideas that work ?