Actually the swelling normally takes a while. Some of the other solvents
will begin to dissolve the seals, but alcohol will not.
In using any kind of chemical cleaner the key is to keep your immersion
or contact time as short as possible, and to remove it as completely as
possible. For example if you purge your brake lines with alcohol,
a good way to do it is to follow it with DRY compressed air, because
the alcohol is volatile enough that the air will take it all out.
(Temperature is a factor - warm air is better than cold.)
--
George Downs Bartlesville, Oklahoma