1. For maximum vacuum make sure all your seals are airtight. Coat each hose fitting with a thin layer of Vaseline and reinstall the tube. Do the same for the seal on the jar lid. When it gets old and dried out, replace it with a new, standard canning jar lid (drill holes for the hoses).
2. Leave the arm hanging off the back and the vacuum pump switched on between passes (not during long enzyme soaks, just while brushing the other fluids around). Letting the nozzle suck air may help keep the vacuum tube clear (untested hypothesis, but I have fewer thread-pulling issues).
3. The nozzle can get gunked up on the inside. To clean, trim the bristles on a pipe cleaner to about half normal height for a length of about 2 inches. Wet the trimmed end and it carefully, a mm at a time, into the nozzle as far as it will go. Scrub.
2. Leave the arm hanging off the back and the vacuum pump switched on between passes (not during long enzyme soaks, just while brushing the other fluids around). Letting the nozzle suck air may help keep the vacuum tube clear (untested hypothesis, but I have fewer thread-pulling issues).
3. The nozzle can get gunked up on the inside. To clean, trim the bristles on a pipe cleaner to about half normal height for a length of about 2 inches. Wet the trimmed end and it carefully, a mm at a time, into the nozzle as far as it will go. Scrub.