Protecting Equipment from Children

@geof3 nailed it. Constant surveillance. There is no substitute. 

My grandson stuck Play Doh into the rear port of a speaker and ran off.  Only his three year old hand/wrist could fit into the port and he wasn’t interested in retrieving it.  On the other hand, the Pay Doh was revelatory, as if a veil had been lifted, and I now recommend it to everyone as a tweak

Just how big a load of Playdough are we talking here? Multiple trips or just a handful? You may never know.

How far into the port? 

When my children were young I kept a picture of my mother in law on the mantlepiece. Kept them away from the fire......