In article , tenplay says...

Last summer we had the exterior of our house painted by an acquaintance,
who was starting her own house painting company and has since gone out
of business. She was rather sloppy and left some paint drippings on our
deck, which is made of artificial wood (TREX). What is an effective and
inexpensive way of removing the paint drippings? Thanks.

No surprise she went out of business...