You can clean these tubes out with a 5/64" drill bit, which is just under 2 mm. Individual drill bits can be bought at Lowes or Home Depot. If the clog is 3/8" or less in length it can usually just be pushed out by inserting the drill bit, without a drill attached, and the placing a pair of pliers around the clog. Push the entire affair against a table or counter with some force.

Longer clogs will have to be drilled out SLOWLY, again gripping the tube around the clog with pliers.

I am still on my original set of tubes after 6 clogs.