Do you also believe that playing in the mud is good for your child? My wife doesn't let my two-year-old play int the park as she fears that he would get an infection?

it's not bad to feel the touch of mud for kids. but parental supervision is always necessary, make sure you give good bath after playing and keep checking kid is not putting his dirty hands in mouth or ears.

I can't say it's good, but it wouldn't harm right. kids learn best through kinetics not audio. best to get them hands on.