To get started, you'll need to decide what bathing method your dad needs. The three main options are the shower, the tub, or a bed bath.

Learn the ropes from a pro if possible. What works best for your dad will depend on his health, mobility, mental state, and strength. Consult with his medical team to come up with a plan. Get all the input you can to make your job easier. It can be very helpful to hire a home health nurse for a onetime bathing crash course.

Assess his abilities carefully. Consider his balance and ability to stand; any joint stiffness and pain he experiences when bending, sitting, or reaching; whether he has sufficient fine motor skills to use soap or a washcloth; his sensitivity to water temperature, which can decrease with age; the presence of sores or wounds; and his mental state. People with Alzheimer's or dementia can experience severe anxiety around taking their clothes off or getting wet. Alzheimer's can also affect depth perception, making people fear the bathtub, thinking it's a void.

Don't insist on a rigid schedule. "In every situation, you need to evaluate before you do anything. It's really pretty easy to do," says Balestreri. "Sometimes it's a day-by-day thing, and by the end of the week you have all the body parts clean. You never want to force it."

Offer a shower if he's up to it. If your father's in pretty good shape, he may be able to shower largely by himself with you there as a kind of spotter. Stay on the sidelines to allow him privacy and independence, but within easy reach in case of an emergency. Bring a newspaper or book, but be on the alert. If he protests, explain that it's better to be safe than sorry, and you're there "just in case." Don't let him talk you out of staying. Bathing accidents are all too common for elderly people, and most are preventable.

A tub or shower seat helps if he's weaker. For certain weak elders, sitting in the tub or on a shower seat is the most comfortable and practical way to bathe. The shower is preferable, as it's much easier to get in and out of than a tub.

Opt for a bed bath if he's very frail. If your father is extremely frail, he may need to be bathed in bed, a process called a bed or sponge bath. There are different techniques, but the basics involve washing and rinsing with washcloths.