The single most expensive thing people learn by ruining something.
There are three families. Water-based is compatible with everything — every condom, every material — and only needs reapplying. Silicone-based lasts far longer and works in water, but bonds chemically with silicone surfaces and degrades them, leaving a permanently tacky, unhygienic finish. Oil-based destroys latex condoms outright, within a minute of contact.
Material matters as much. Body-safe means non-porous: medical-grade silicone, borosilicate glass, stainless steel, ABS plastic. Porous materials — jelly rubber, PVC, anything labelled only “novelty” — cannot be fully sterilised, because the pores hold bacteria that no surface cleaning reaches.
