@Serif
Here are the things you can use fromfree to a few dollars tools.
1. If you have a long flexible shower head, then take off the shower head, clean the hose head, run slow warm water,( water volume like water fountain, try to count the time to fill up a cup, so you have some idea of how filling speed.)
Stoop down and let the water in.
2. Water bottle, remove cap, put a plastic wrap on it, poke a whole, lube it(plastic top & your hole) with lube or cooking oil, stoop down or just seat on it. Thin plastic battle only. (Poland spring 0.6 litter the best)
3. Go to home depot/ hardware store, get a copper fitting that secured to a bottle cap. ( reusable) i do NOT like this one that much, because water flow back to the bottle too.
4. Go download alliexpress, buy a enema cleaning tool or bag or hose connector ( cheap)
Have some cleaning fun.
Do Not try to flush the entire large intestine in one short.
Advise, 1st round, 1 litter or 1 qt, then let it go,
2nd round can be 2 litters or 2 qt. It will get most of the soft paste out,
3rd round can be 2 litter or 3 or 4, you body will tell you the limit, do push the limit, don't burst it, keep yourself in a comfortable level. ( in this case more DOES NOT mean better) make sure water is clean enough.