If those are the ones with the built in cone this won't work.
For reg cartos, there is a syringe with a soft rubber cone attachment for dosing kids that you can get at the pharmacy.
The end of the cone fits over the batty end of a carto perfectly.
Then simply run hottest water from tap into a bowl and draw in / push out
through the carto about 20 times and you're done. Let dry a couple of days in a warm spot and you're good to go.
