Slowcooker ? Never heard of it! Did you ?
For guests or a family: use the big one. For us singles, the small one will do just fine. Put your diner in it in the morning, put it on slow and off you go for the whole day. It will be totally safe, energy used same as for a reading lamp. If your recipe asks for 4 hours, use the timer fit for putting your lamp on when on vacation.
There are lovely cookbooks – read the entry for proper use of your slowcooker – as for recepies Google away!
Here two cookbooks
How did we ever survive without them I wonder???