If you want to try a disposible enema, it contains ingredients that force you to have a bowel movement, so you can't hold it for very long, however I doubt you would want to hold it longer than 10 minutes anyway.

I started out with water enemas, and can hold them up to an hour.
I'm trying to hold three litres, but it's very hard.

When you give yourself a water enema remember to check the temperature, 105 degrees is sufficient. Test the water as you would a baby bottle, on your wrist. Colder enemas result in cramps.

Your body will absorb the water you put into it, so it's always best to put a little salt in the water to avoid the risk of elecrolyte imbalances.
I also like to drink gaterade while I'm having one.

When expeling the enema, don't push it out, let it come naturally, times vary for everyone, and don't expect to think you are all done, because sometimes you aren't

As for butt plugs, it's a comfort level for everyone. How big you can take, how long you can keep them in before you become uncomfortable.
Regarding cleaning, always clean right away after taking it out.
Soapy water works best for me.
For anal beads, I sometimes boil them in vinegar.