Take a 30 minute shower. Wet yourself thoroughly. Take your time wahing. Soap yourself all over your body.
Have a vibrating butt plug and dildo inside of you... at max. Have plenty of batteries.
Every 3 minutes, when under the water stream, slap yourself with a wooden ruler (preferably), a wooden bar, or at least spoon (thick side) 10 times in each tit plus 10 times in your pussy.
You must use all your strength when giving these slaps... Don't do wimpy fake slaps, strike as hard as you possibly can.
When it comes the time to dry... let evaporation do it's magic.
Keep every internal door of the house wide open. Keep every light on. Keep every blender wide open.
When you get out... you must be dripping all over and still naked... with your plug and dildo deep inside of you, vibrating at max. Go out to the kitchen... Prepare yourself a snack... Eat it...
Then go to your bedroom and give yourself 100 slaps in each tit and in your pussy... Exactly like the ones you got in the shower.
Oh! Yes! I almost forgot! The water must, in any way you possibly can, be freezing cold.