Instructions for campmaster portable toilet?

Hi, having bought from a Bigletterofthealphabet shop a campmaster portable toilet, we find ourselves wondering about the instructions. Under the lid it says to CLOSE the divider to the lower tank, pump water in, presumably making a puddle of water to receive your .. offerings ..., then OPEN the divider, flush, then CLOSE the DIVIDER again until the next time.

In the booklet it says to OPEN the divider, do what you need to do, flush and then CLOSE the divider when all is done. The booklet instructions make more sense to me, but we are puzzled as to which one is correct.

Returnign to the shop won't help, they are clueless about most of the camping stuff they sell, apologies to Bigletterofthealphabet shop employees.

Never having used one of these before, we are anxious ot do it correctly, not wanting the proverbial to hit the fan.

Anyone have any experience with this?

Thanks, raindancer