You will need:
An empty water bottle
An old terry rag
a rubber band
a pan or dish or water
a pan or dish of dish detergent
Cut off the bottom of your water bottle...about 1 or 2 inches up from the bottom.
Cut a piece of rag large enough to wrap around the bottom of the bottle where you just cut, and up the sides enough to be secured by the rubber band, now secure the rubber band over the rag thus closing up the opening you just cut.
Pull the rag tight against the opening.
Dip the rag end into the water get it good and wet.
Now dip it into the detergent and let it soak some up.
Now blow and blow and blow from the drinking end and watch the suds worm grow.
Chloe loves to do this...this is the 4th Summer we have made mile long suds.
NOTE: The last photo is of the year we used Dawn as opposed to Palmolive, in my opinion Dawn makes a much better suds worm.