full vac is not good. and not nearly necessary ... at lowww temps. maybe like under 80F you can go full vac and be safe..
what kind of sized batches are you guys purging? small batches/thin film, you can go pretty quick.
for shatter. i believe in thin film.. QUICK thin film, at a regulated pressure/heat..
for wax. i like to make honey combs :] i dooo not know of an automatic way. but! i basically like to get to foggy stage, past shatter. THEN, i like to fold it into ball, let it cool down, put in chamber, get to my desired vac, under 29 HG with no heat, then place my chamber into heat, (100ish F) let my muffin under vacuum melt down as slow as it needs to.. ( i feel the lower you can finish on the vac pressure, the prettier outcome you get.. ) and ya.. these muffin melt downs under vacuum tend to purge reallyyy well for me..
i feel like the muffin collapsing onto it self, while under vac/warmth does a greatttt deal of work..
my chambers need to be tuned..
but with a good chamber, i can usually lock my vac off at 29.5hg. let it sit over night in heat, and wake up to honeycombs with vac pressure around 28+.
now, with my non sealing chambers, i like to run my vac all night, and bleed at 29HG .. wake up, combs..
there are a million ways to do it! ive been playing with no vacuum honeycomb making as well.. and ya.. well.. my no vacuum honeycombs tend to be a bit more contaminated, but quite good in consistency, color, taste..
all in all, me thinks the vacuum way is the cleanest way :]