Here’s a polished version you could use for your announcement:

🎃👻 Join us for Messy Play – Halloween Edition! 👻🎃

Get ready for a spook-tacular session of sensory fun!
✨ Halloween-themed mess in our tuff trays
✨ Safe, creative play for little ones
✨ Dress-up if you dare(but not required, and spare clothes are a must!)

Spaces are limited – come join the fun and let’s make this Halloween wonderfully messy! 🧡🕷️

Limited space in the hall for prams.