The kit looks like it would be better than not flushing at all. But I don't think it does anything more than what hooking up a nitrogen cylinder would do. Think of it this way. Technicians for my company flush $500,000 1000 ton centrigul chillers with old fashioned nitrogen cylinders, and they are cheaper than that kit at $270. The kit may work just fine, probably does, but having never used it , i cant say for sure. If it were me (just my 2 cents) I would clean and purge as much of the unassembled system components as possible then assemble the whole system, draw it down for 24 hours,break the vacum, then purge with nitrogen with a break in the system probably at the suction line of the compressor, reconnect then draw it down to 400 microns make sure it holds, draw it down..it creeps up...draw it down ...it creeps up etc...until you draw it down and it stays down if it does not eventually stay down it has a leak. Then you have it ready for refrig. Then the key is to have the system vacum draw whatever you want to put into the system into it. Opinions on this vary a great deal, the bottom line is that you have to get as much moisture and contaminates out as possible. Automotive systems are very robust and can stand alot more than some other systems. I know of one person that vacumed a system down for 3 hours, no flush, and have been running fine for years. Most commercial gas, HVAC shop, or welding supply can get you a tank if you decide thats the way you want to go....