i saw a video of this "freshwater dolphin" on youtube the other picking up ping pong balls with its nose and throwing them through a glowstick ring... i'll try to find the link.
i used to do it to my oscar to distract him so my other fish could get a decent amount of food before he vacuumed the food up. other wise he would just push it around and try to eat it
Youll be doing good to keep an RTM from hiding 24/7 or at the very least, being spooked easily, let alone being interactive.
I think the ping pong ball excercise is for more social/interactive/owner responsive cichlids like oscars & midas. I saw on funniest home videos one time an oscar spitting a ping pong ball into a little home made basketball goal repeatedly...and Ive looked for the video for 10 yrs but cant find it anywhere online.