Shooting on a white background? The background usually isn't the problem - the lighting is. Three fixes for most gray-or-tinted-background shots:
One soft light at about 45 degrees. Mixed color temperatures (window + desk lamp) leave green or orange edge casts that read as a dirty background.
Pull the subject 30-50 cm off the backdrop. A tight gap throws a hard contact shadow; distance lets the light wrap and the shadow soften.
Expose for the background, not the subject: raise exposure until the histogram's right edge just kisses clipping, then pull back a touch.
Quick test: tap the darkest edge of your subject and the background - if the background sits near the right edge without touching it, you're set.
I build CleanWhiteBG (https://cleanwhitebg.com), a free browser tool that cleans up white backgrounds in one click. Disclosure: my own product.