patching radial tires- LONG...?

I've worked in a couple different tire shops and the reason they don't
like patch in a can isn't because of the propellant used (it used to be
very flammable and dangerous especially on the old steel rims) but that
if the tire is coming in and you had to put a patch on it to you have to
clean the surface where the patch was going to give it good adhesion but
the fix a flat would be a gummy gooey mess in it since fix a flat is
like an uncured latex it just sticks to everything that come in contact
with it and takes awhile to clean it right then you have to clean the
whole tire out since fix a flat is only a temporary fix to get you to
where you need togo to fix it right and is possible to throw your tire
out of balance too which in my experience seen only once but is still
possible to do .