Shaving cream sensory play fail

In talking with Liam's OT, she encouraged me to do more messy sensory play at home.  I had to do this with Thomas when he was younger too and it helped him a lot with having paint on his hands, sticky food etc.  Liam though is much more strong willed and he sure exhibited that today!  

I dug out some shaving cream and asked Thomas to join us in the activity so Liam could see that big brother could do it.  We covered some baking pans with foil and squirted shaving cream on top.  Immediately Liam looked concerned.  He loves smells so I poured some pink kool aid mix into it, but this did not help.  Thomas put his hands right in, but Liam just observed.  Eventually I got him to stick his hand in for about 2 seconds.  He flipped out, wiping pink Kool aid shaving cream furiously all over his clothes to get it off his hands.  Looking back, I should have let him start with some toys to play with in there rather than go for putting his hand right in.  Will try again another time.