Yes, Shitboi, those soap sticks are definitely more effective as a stimulant but even more as a disciplinary threat. I remember getting enemas from about 6 or 7 for constipation relief but also stomach aches, fevers, you name it...measles, lol.
My mother used to drag me into the bathroom for bad behavior too. The combination of her taking control of my body and pride plus the degradation of her watching me take a 2qt enema on all 4's in front of her should have made me straighten up but slowly and secretly I began to enjoy the contact, that soothing hot water and her making me retain til my next birthday!
She had heard about soap supos from a neighbour and decided to try them out on me. Next time I acted up I got a surprise. She had whittled half a bar of Ivory to a smooth torpedo and after a brief soaking and explanation of the process (more to get me anticipating agony) it was inserted as deeply as she could with her finger. She would remove her finger but squeeze my cheeks and make me hold it in me for up to 10 minutes on a timer. Apparently I must have squirted one out early one time as I remember her keeping that finger in there til they went off after the first few times. The burning was intense but all I could was squirm on her lap as she sat on my bed. Unlike with enemas, these were administered on my bed mostly.
By 11 I was definitely finding the sessions arousing and my erections gave me away. One time she was twirling the soap bar inside me with her finger for more stinging and I began rocking on her lap. She ignored that for a bit then withdrew her finger and said something like, "Why you little stinker!! You're enjoying this aren't you?" Words escaped me but she could tell from my red face what she had been feeling on her lap was a growing boy with a budding interest in enemas and insertions.
She was pretty cool about it though and told me that either she was going to have to come up with a stiffer ( no pun) punishment or else use this treatment as a reward for being a better boy. For the next year I was the model son and we enjoyed our secret bonding times. It all seemed to fade though as I got into puberty for some reason I still don't understand. I never came in her presence but, oh, what masturbation material those sessions were in later years. And those soap bars still ring my chimes years later.