Not been mentioned but best to use a plastic container for the process. No point in using the cleaning power of the citric acid to clean a rusty bucket!
I filled an old deep fat fryer with a citric acid mix (not too strong) and used it to heat the mixture & the parts up to 70 deg c before leaving the parts in overnight to be cleaned.
It worked very well but the chip basket started to dissolve after a few days! It wasn't stainless steel but chrome plated mild steel! I left the mixture in the stainless steel tank for a month or 2, thinking it was safe - it dissolved the heating element in the bottom of the tank!
Lesson learned - only store it in a plastic container!
Handy for cleaning up wood & also hot grinder particles that got blown onto a white works van thought I was far enough away & van is still perfect long after the incident.