When I use a toy the most important thing is to remember if you've had a BM in the recent past. Sorry to go here but... I go once a day in the morning regularly, so if I plan to get a prostate massage in after I've done my business, then things are ok. If I do anything before that... well it can get messy. You should have no leakage or anything gross like that and I've really found in unnecessary to do any anal cleaning if you follow this simple rule. I also always enjoy a nice shower afterwards,

I would not personally recommend anal douching. If you do decide to do so, be sure you read up on safety precautions (such as not commencing activity until well after you douche). If you get a good amount of fiber (you can drink Metamucil to supplement) in your diet, you're not going to have much if any residue in the first few inches of your rectum, where your prostate is. You can use a finger condom or glove to lightly clean the inside of your butt by fingering it a bit in the bathroom (using some lube of course). This will also get you somewhat pre-lubricated for whatever activity will follow. Occasional residue is a reality of anal play. It's something most people just deal with.

I began douching or rinsing out my ass, several months after I started prostate play. I just like the idea of feeling clean. I use a bulb enema, fill it with hot water, lube up the tip, insert, squeeze out, release into the toilet. I repeat that three or four times until the fluid is running nearly clear.

Then before I start to play, I wait a little while. When I'm ready I lube up the toy and insert and away I go.

It doesn't take much time, but I like the feeling of a rinse out and fee more comfortable playing with my ass afterward.

Or rubbing against the anus, leading to pain and a raw feeling. That's why I recommend checking things out first - if there's stuff in there then either deal with it or put off the buttplay.