What is a good remedy for bed sores?

No single treatment. Well there is one thing all bedsores need: relieve pressure! after that the depth, 'stage' amount of drainage as well as other factors determine the treatment. Probably best to have a consultation with a wound specialist on short order to get everything going in the right direction.
Pressure relief. There are different stages of pressure sores with stage 4 being the deepest and requiring aggressive management. Sometimes there is bone infection called osteomyelitis requiring intravenous antibiotics. Some patients may require surgical clearing of dead tissue from the wound base. Pressure relieving mattress may be required for effective healing. Nutritional protein supplements may also help.
None. Treatment of bed sores requires a multifactorial treatment plan. There is no one remedy.