Realistic sex dolls for men are made from safe and healthy materials. You should pay attention to product hygiene when using it, because it will not cause any harm to the human body.
The Real Doll with inner canals is a bit more difficult.
It's a good idea to wash the inside and outside with warm water and soap just before use. My fingers and liquid soap are typically used for internal canals. I've found that drying the insides of life size sex doll that don't have two open ends can be tricky. I like to use either tightly rolled paper towels or rolled up washcloths.
Be sure to repeat the above process immediately after use. The inside of the dolls should be completely dry before the female real doll is stored.
This might seem like a lot of hassle, but the rewards are worth it, at least to me. It is definitely important to take care of yourself and your body. It's definitely a good idea to use lube. It's a good idea to choose a size to start with.