I'm not sure exactly what film you have but I have used x-ray duplicating film to enlarge negatives for pt/pd printing for many years. It produces a negative from a negative. It is an excellent film despite being very slow and on the expensive side. I use it with Kodak GBX dev. and fix with water as the stop bath. What I use requires a red safe-light. Remember more exposure yields a lighter negative and thus a darker print. I find the dup. film to be superior to digital negatives. Consider the chemistry as a factor in your "occasional success".

Because you can't really tell if you got it right until you make your final print there will be a learning curve to read the negative. Use the successful ones as a guide for tonality. Manipulating the film (burning/dodging) is like making a print but because it is a reversal film you just do the opposite. I would expect it to work as well for albumen prints as for pt/pd.

http://www.jeffreyglasser.com/