I am making new ash treads for the stairs in the house I am working on. The original treads are some kind of softwood with a million layers of paint and have worn as much as 3/8" down from flat in places where people have stepped the most over the last 100 or so years. I'd like to find a product that I can apply to the steps on a Thursday before I leave and that will be ready to walk on on Monday morning when I get back. I'd rather apply the finish once the treads are in place and the plugs are put over the screws, but I might be able to pre-finish them and then install if that would be significantly better. Rubio Monocoat looks nice except I don't know how long it is before I could walk on the stairs again, and putting down cardboard or a drop cloth on these steep 9 foot high stairs seems like a ticket to an undesirable destination. I'll be grateful for any advice.