Good idea: Letting go of my anti-mess complex to let Red Chief use watercolors during General Conference this weekend. They actually worked better for us than crayons, because crayons are still being eaten at this stage.
Bad idea: Doing it on the carpet. The blanket and sheet worked well . . . until the water spilled. Which, if I had really thought about it beforehand, was inevitable. But, for the record, the spot came up easily and all is well.
Conclusion: We should do it again. But next time with an apron at the kitchen table.