I did it.
you have to know I was uncertain if it will work. So I went to a local garage (West Los Angeles). They recycled the old stuff ($40), did a "die" Test ($25) to see if my AC is leaking/working. Of course it's leaking a bit, but it should be enough for 3 or 4 month. Then they filled in the new stuff and it works. Total cost $200. The next time I only need the regular refill (about $50).
Just try to find out!