Many motor home repairers use it for repairs so I would have thought it would be fine.
If I were you, I'd give the areas to be treated a thorough clean so that the sealer can be as effective as possible. Try some petrol on a cloth first, then some meths to finish up wirh. And dig out any loose bits of sealer before the new stuff is applied to again give a decent seal.
Put the sealant tube into a bucket of warm water for a while so that it flows nicely when you apply it. Wipe the surplus off again with some meths on a clean lint-flint-free cloth.
