Mushroom compost stinks that's what it is stinky stuff - manure and straw rotting. I like it to stink that means it's good stuff. I buy mine in Joplin but it comes from Miami, OK. I don't think it smells like oil or rubber or burning though. . Where did yours come from. I have purchased bagged stuff that had a chemical smell and I don't like that.

It's good weed free (or usually) composting mulch. I like it :)

And a year or two after you applied, you'll see plants really jump...assuming you used it heavily.