Todays plastic food containers are good to go and microwave safe. Glycerin soaps will not stink up the oven.
I thought there might be a couple hams here. i'm testing for tech next month! as far as the soap goes though, i thought taking the Altoids MINT tin a bit further to add a couple drops of menthol to the soap might hold the soap true to it's label
Yes, soap left in altoid tins can rust. Trust me... I found that out on a camping trip a while back. The previous winter I melted either VDH or a glycerin soap into the round altoid tins that were available at the time. Then after a season in storage I went out on a camping trip to find everything in the soap tin rusty. I applaud your effort! You are on the right track.. but you can still get smaller! This isn't my smallest set up. I also have one of the small 4 piece razor kits where the handle comes apart and fits inside itself. However, I don't take that kit on the road. The handle is too slippery when using soft water. Shaving sticks are good for the road. If you keep your VDH puck in the plastic container it comes in, it packs small enough as well. Anyway, here is my current traveling kit. Yes, the handle on that brush is just a brass fitting from the hardware store. I can actually get a longer tech handle in the case, but I prefer the head to have more cushioning. There are four compartments separated by sheet foam. The top and bottom are lined by sheet foam as well. The two vials in there are witch hazel and TSD Iced Subzero. There is enough there for about 3 shaves. And yes, that is cream in an Easter egg.
This was my first thought too - rust. Especially with all the water involved. Just a random thought here... what about a plastic chew "tin?" I think an old, well cleaned plastic skoal case (round) would be perfect. Small, round, no rust...
If you did melt and pour you would want to be careful - but you really don't want to get your soap too hot anyway. It should be fine. I had meant to grab one of the round plastic mint containers to try, but the lids don't pop off nicely. A chew container should work well. (I quit that about 20 years ago, so I don't have any around)