Hi Eric
The main problem is customer’s expectations.
I have a leaflet from a know brand “offer the most advanced protection against general soils & common household spills. The treatment may not prevent staining from hot drinks, some food dyes, acid, bleaches, solvents & some other chemical or pharmaceutical substances” this as I said from the leaflet it is not on container.
I inform my customer’s of the above it’s not a special miracle thing & it does in time wear out just like your shoes.
Nigel_W has valid points, especially on responsibility.
If there are products out there which covers all the mishaps please let me know.
Good luck with you new venture.
Len