My typical wipe purge setup is to purge behind a bungee cord which knocks the string off when the tool moves to the brush. The brush is the silicon basting type and meant to be a secondary attempt to knock off a string which may still hang on. This worked about 95% of the time for a large print. However, I would really prefer to have the entire tip of the nozzle wiped clean. My cohost suggested using silicon foam. Same 600C spec as the brush. They sell sheets of the stuff for T-shirt machines. https://www.amazon.com/gp/product/B07D1CFM9F/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&psc=1 I made a shoe holder that slides into the brush holder. The foam is held by the sides of the shoe and it's positioned right at the point of the nozzle with just a bit of pressure. The pressure is enough to get the nozzle to etch a path into the foam and with my zig zag wipe I get a nice wipe around the entire nozzle tip. Now I not only get 100% of every string, I also get a very nice clean initial extrusion on the start of the tool path. Great stuff!