My MIL swears she had my hubby potty trained by 5 months old. I think it was just figuring out his times.
I think it is impossible to train a child until they are cognitively able to process the whole thing.
When training a person with a developmental disability it takes a lot of discerning to determine at what step they need to start a task. Take for an example brushing teeth. To do this task what does a person need to do before they can say they actually know how to do this???
first of all they must recognize it's time to brush their teeth
they need to go to the place they brush their teeth
then gather what they need to do the task such as toothbrush, toothpaste, etc.
they also have to be able to hold the toothbrush, put the toothpaste on the brush, turn on the water, set the water temp to a medium temp so they don't get burned or hurt their teeth with water that is too cold, wet the brush with the toothpaste on it without loosing the toothpaste into the sink, then do the brushing in a thorough way.
After they do the task they need to clean up, then go about their business.
So something as simple as brushing teeth has many complicated steps.
Potty training takes a lot of these same mental abilities. Your baby does not have the mental ability to do this. He is too young and it will be nothing more than just catching him at the right time. If you are busy cooking dinner or switching a load of laundry out and he squirts poop all over the floor and starts playing in it or finger-painting with it you are going to realize just how ludicrous this task is.
When he is breaking out it may be the laundry soap or fabric softener you are using if it's cloth diapers. If it's from disposable then it's possible he's allergic to the materials or fragrances in them. There are many possible causes so don't just give up and do so much work.
When doing the potty training, a lot of us put boys on the toilet seat backwards and it works just fine. They get the idea they are supposed to face the water tank this way so when they start standing up it's just a normal thing for them to do.