In article , "doozer"
says...
snip
I actually bought some sealant and was going to give it a go on a small
section but chickened out at the last minute. I wasn't sure it would
match or that I would be able to get it out the gap if I didn't like it.

If you want to try it you could apply some sort of release agent
(wax, vaseline?) to a small part, then apply sealant confident in the
knowledge that it will just peel off. You'll then need to scrub it
with something like white spirit before reapplying.