This technique works. But, for a challenge try putting on a triple cock ring, one that is welded together. It is a real challenge to get it over the balls, shaft, and shaft and balls. Lube is a definite necessity. Once you are hard you cannot remove it, so it is on for the entire playtime!
Put the ring on your cock 1st, then work your balls through the cock ring one at a time. You will get instantly very hard and your cum loads will be more powerful!