Based on what you described, you've probably got nothing to worry about. It's when you ball up rags and the heat can build in an insulated space where you really get into trouble. That's my understanding anyway.
Someone please do correct me if I'm wrong, but I've never heard of a workpiece catching on fire.
I just leave them outside to dry or toss them in the woodstove, the latter being the foolproof method.
+1 Spontaneous combustion fires I have responded to over the years, have all been, dirty oil rags tossed and left in metal storage bins or discarded in trash cans. I posted a lengthy post not too long back about a friends old .22 I refurbished. I used BLO on that stock straight from the can.
I spread a thin layer of BLO on the entire stock in the garage with a rag and let it sit for a few hours and then came back and wiped off the excess oil, letting it dry for 24 hours before applying another coat. I did this 6 times over 6 days, allowing the stock to sit on my work bench with a slow fan circulating over the stock.
After each time, I would take the old rag / rags, I used each day to apply and wipe off the BLO, to the kitchen sink and washed each out each day after I was finished with dish soap and warm water because I was worried about spontaneous combustion.
I threw each one in the trash after using and washing. Surely the dish soap and water broke down the BLO enough to throw away?
Me on third. 
A third coat will be enough, I think. 
