Everything is reusable (in the same session). Just place a bucket or similar object underneath you to collect the run-offs and voila, you have more mess to pour over yourself and get messier. Plus the multi-colour run off adds to the fun of the session.
Saved sludge (if it is fun and artificial, as it should be, such as cool whip and batter with water only) will last overnight when saved as well. No damage done. Just stir it again.
You want something either mineral based or oil based. I am assuming that Vaseline is a no-no, due to being a byproduct of fossil fuels.
You can make a decent slime bit you have an electric hand mixer by combining any cheap vegetable oil with either vegetable shortening or beeswax. Just blend until you get your desired consistency. it's even easier if you warm everything over a low heat before mixing. Then add your coloring.
If you look up recipes for "un-Vaseline" or "Petroleum-free jelly" you'll find lot's of options.
Just beware, this stuff is really slippery and can be hard to clean up. But it will last for months before going rancid.
On the bright side, it's really good for your skin and hair.
You can make a decent slime bit you have an electric hand mixer by combining any cheap vegetable oil with either vegetable shortening or beeswax. Just blend until you get your desired consistency. it's even easier if you warm everything over a low heat before mixing. Then add your coloring.
If my food chemistry is correct, by adding a bit more vegetable shortening or coconut oil (vegetable shortening could have trans fats, if that's something you care about), you can create basic margarine. I'm sure there are other ingredients needed to make it table ready.
For non-wasteful, low-impact, environmentally friendly WAM, I'd second what MoMud said. Easiest is outdoor mud but even indoor, you can mix up some modelling clay and it will keep for months without going off - while things like custard generally start to smell bad within a few hours of being first used.
As a teenager I had a fairly low-impact WAM lifestyle, I lived on the coast, so I'd dress up in my "to get muddy" clothes, with a clean change in my saddlebags, ride my bike out along the coast to some secluded mud pits out of town, park the bike somewhere out of site of the road, go and wallow in the mud till I was totally covered and done, then change into the clean gear (most of the mud came off with the mud clothes, and I wasn't fussed about being a bit mucky as long as I could get dry clothes on - usually a track suit), take the muddy gear down to the sea and wash it out in the salt water (I'd have my trouser legs rolled up and put my muddy wellies back on to go into the water, so they and my feet got washed too) - seawater is amazing for washing mud out of clothes - out of the water, boots and wet clothes in plastic bags on the bike, dry socks and trainers on feet, cycle home.
Meant that the clothes I eventually put in the washing machine were just wet, no longer muddy. And of course I could do this over and over, no cost and no waste.
Love you, too
What do you guys suppose are the best things to get messy with and re-use to get messy with? 
