Yup, really sounds like some messy sensory play might help.
Put towels down on a tile or lino floor, provide a basin or baby bath of water, cups, jugs, funnels, pump dispensers etc. etc. You might get some quiet time. Afterwards wipe down the floor with the towels and throw them in the washing machine. Bonus: mopped floor.
Other ideas for pouring and soap fun:
A basin of dry rice with cups, jugs, funnels, spoons - bonus: no floods
A basin or tray with shaving foam - bonus: clean hands
Squishing fun:
A strong ziploc bag containing some clear liquid dish soap or similar, glitter and small water tolerant toys. Duct tape the bag closed. Bonus: no mess.
The first time I gave DS play-doh, there was 20 mins of complete silence and concentration. It was unreal!