Here is the best way I've found to do it:
squirt a bit of aerosol carb cleaner into the fuel inlet for the accelerator pump circuit for that carburetor. I used a good vacuum pump (set to "pressure" iso "vacuum") and slipped the hose over the metal tube which goes into the inlet hole. The idea is to pressurize the air and carb cleaner in the circuit to help push it through the tiny little jet. Let it sit for a few minutes and repeat. Don't go overboard with the pressure. I then used a very fine pick to reach inside and around the jet to where the little hole is and pricked the hole while everything was under pressure. A piece of fine wire or an office staple will work well, too. One little prick and everything opens up (it did for me). You'll get a spray of carb cleaner from the hole, so do wear safety glasses! That stuff hurts when you get it in your eyes!
That's what works for me.