dishwasher safe?

Probably however your best bet is plain old soap and hot water or a toy cleaning spray. Pretty good material in that it holds no bacteria at all.

If you want jelly soup, sure.

As it is Sil-A-Gel (aka jelly with antibacterial agents), it cannot be entirely sterilized and cannot be boiled or put into the dishwasher. Soap and water or a toy cleaner is your best route. While Sil-A-Gel has some antibacterial agents, it's not completely self-cleaning.

Jelly is porous and can house bacteria.

I've had jelly toys melt on me just from storing them during hot weather. The heat from the dishwasher would almost certainly ruin it.

This material can't be disinfected anyway. Use a gentle hand soap and warm water. Make sure to keep it in a clean, cool place. I store mine in a plastic bag so it doesn't attract fuzzies and dust.