It’s possible to use others, but we recommend against it. Our formulas contain no dyes, phosphates or optical brighteners, and will produce optimal cleaning performance when used in combination with BISSELL carpet cleaning machines. Carpet manufacturers also recommend the reapplication of stain resisting formula at least every two years, and BISSELL brand carpet cleaning formulas are the only ones that contain Scotchgard™ protection. When these formulas are used with a BISSELL ProHeat® series carpet cleaning machine, this combination produces the only consumer-use carpet cleaning system that maintains the Scotchgard™ protection carpet stain warranty. And at an approximate price of 2 cents per sq. ft., the cost is relatively minimal.