Just a quick post today.
Soap sitting in water is a fast way to have it dissolve. I've come to find regular soap 'dishes' have shallow ridges and closed edges which allows a lot of water to marinade a bar of soap. When this happens, the soap dissolves / erodes quickly unless you're vigilant about draining your dish.
If you're going to switch to bars of soap, I highly recommend you consider this when selecting a soap dish. You can find open style dishes that are expressly designed to keep water away from a bar of soap. Similar to a dish drying rack. They also make silicone trays that sit under these racks to help catch water and drain it into a sink/bath tub/shower. Much like the trays that sit under dish drying racks. They even make soap baskets that suction cup to tile if you have a shower with no good spot to put a bar of soap.
These products can be found cheap, easily and make a huge difference. I'm getting 1-2 weeks of extra life from a bar of soap now that they aren't sitting in water after use.
This seems odd, but it's a big deal if you're a soap lover.