This is how I clean.
1. Check for any loose threads / or soiling - remove.
2. Throughly vacuum mattress, base and underneath bed (you can extend this to covers pillows etc,) -
with Kirby or similar, if you have a soil trap show customer its quite impressive.
3. I have a sterilaire UVC system for sterilisation of surface areas.
4. Lightly spray nice smelling antibacterial suppressant.
regards
Mark