I don't. I found a conditioner that doesn't build up and rinses clean with my co-wash.
If I try a new product that builds up, I just borrow a bit of whatever sulfate shampoo my roommate is using. She's a curly, so it's usually pretty gentle.
3C/Fine to Medium/Low Porosity/High Density
CJ Gentle Cleansing Shampoo
DB Pumpkin Seed Curl Moisturizing Conditioner
CJ Smoothing Lotion
Queen Helene Sculpturing Gel & Glaze
No Salts, No Waxes, No Butters, No Heavy Oils
No ACV, No Saponified Oils, Protein Sensitive