Use lots of pumice-soap, warm to hot water,
and scrubbing (with a plastic-bristle-brush or a pumice-stone)
to remove Great-Stuff-spray-foam (insulation) from your-skin.
It can take a few-days.
Petroleum-jelly or vegetable-oil can be used to soothe your-skin.
Some organic-solvents (like acetone/nail-polish-remover) can dissolve uncured-foam,
but unfortunately they are more-HARMFUL to your-skin.