Look for a collapsible silicone foot soaking bucket instead. They are incredibly lightweight, fold completely flat, and usually feature built-in carry handles that make transport much safer. Another great trick is placing the bucket on a rolling utility cart so your dad never has to carry heavy water across the room. He can easily fill it at the sink, wheel it over to his chair, and wheel it right back to the drain.
I got the references here:
https://hopebridge.care/navigating-hygiene-concerns-with-elderly-parents/
https://www.wikihow.com/Clean-Your-Feet
https://qualitypodiatry.com/senior-care-foot-health/10-proactive-foot-hygiene-tips-for-seniors-and-staff-in-nursing-homes-and-assisted-living-facilities/