Butyl rubber can be had in caulking tubes but it never dries and is quite a mess sticking to everything. It does easily clean up with mineral spirits.

My choice for a removable repair is DAP brand Dynaflex 230 found at a home center. It can be had in clear / white / gray / almond / brown / black and maybe another color. This stuff isn't latex ( that dries hard ) or silicone ( that resists paint can never cleans off ) , it is more of a rubbery elastomer sealer. It cleans up easily and flows great.

It isn't rated for automotive use but I've used it all over a car since it is just like body seam sealer. At $ 4.50 a caulking sized tube , it's a great deal and works on houses too!