RSO is Rick Simpson Oil. It’s a cannabis oil or cannabis concentrate. Plenty of info on OG and the interwebs. I even posted a “how to” HERE.
For your situation, the steam won’t affect the final product, but it will likely fill your home with a wonderful aroma for quite a while! Just spread it as thin as you can on a large cookie sheet. If you have some parchment paper, you may want to line the cookie sheet.