I'm new to the board, but have grown and killed orchids for a number of year; thankfully, grown more than killed.
I have a Den. parishii that has four growths totally covered with gorgeous pink flowers. The plant also has three bare stalks from last year and one stalk from the year before that.
How long should I keep the bare stalks before cutting?
If you mean the canes, do not cut them. Leafless canes are still alive, or should be. They support the plant. I don't know about this particular species, but many Dens can also rebloom on previously bloomed and leafless canes.