An increased demand for that kind of process for the dearly departed should lead to increased supply of the chemicals required to achieve that end. Consequently, it more likely that the procedure for making some folks conveniently disappear should become a lot more accessible a larger number of interested parties.
Just don’t do it in your upstairs bathtub
Shortage?? Sodium hydroxide is already produced in multi-megaton quantities. Dissolving a few corpses won't even dent the supply.