Unfortunately any of the Lush products which would make bubbles (such as their bubble bars) contain sodium laureth sulphate (SLS) which is quite often majorly irritating to people with sensitive skin. Lush insist that SLS is a "safe synthetic", but anyone who has found that they react to it would probably disagree!
Have you tried the E45 foaming bath milk? It's SLS-free, and does produce a nice amount of bubbles![]()
I have quite sensitive skin and get on great with lush products and not much else. I have tried the baby bubble bar with LO. Think its called Ickle baby bot. Its meant to smell of lavender so we used it when trying to find something for his evening bath. I only used a tiny amount tho, think i got 4 or 5 baths out of one bar. It seemed ok but as we are so tight for cash I have to totally limit myself on lush stuff just now as i can easily spend upwards of £60 in one go. DH dreads it when i come in with lush bags
ETA: think the bar cost a little under £2 but not totally sure