Concur! BTW, I just ordered and received some reinforved vinyl trim material to cover/protect my two dobs. The stuff is great and only .44 per ft. I got 25 ft for less than 16.00 including shipping.
I have also put aluminum flatstock, 1"x1/8" thick, curved to match the inside diameter of my 10" dob at each end. One to mount the spyder through and the other to hold the mirror cell. These greatly increase the rigidity of the tube.
I didn`t peel the waxed paper on the inside of my 10" dob as the wax seemed to have already melted (it was an older tube) and simply put a couple coats of polyurethane and then flat black latex. The 6" dob however was a new piece of sonotube and the wax layer peeled off quite readily. It left just enough tooth that after the polyurethane and flat black coatings it is exceptionally black!

Walt