Update: Wow, switch issues already on this! I really never expected much of this build, but didn't expect troubles this early!! Turns out, the gap between the switch rod and the shaft where the rod travels is causing too much play sideways. Not good. Intermittent contact, and I bet this is where aldouss/pie-key improves his switches. Kudos to him for making it work! But I don't think I like these flimsy switches, I'll stick to proper footswitches next time. Just a heads-up, in case you guys were wondering at all.
Anyone with a DPDT footswitch to spare? PM me.
actually there's no behind the secrets in these switches..... what you need to do is just disassemble the rod and take some time cleaning the terminals..... this is a bit tricky..... the contact plates are small...... and when not given proper cleaning, just might make things worst.... the way to do that is by using a bit rough pencil eraser and trying to erase the dusts and dirt in the terminals.....
note: this happens (corrosion) only on cheap brands of switches... mostly made in china ones..... i saw eventually tested them.... and proved that the BLACK ones where really that bad..... to be exact.....
and sir SIORE i use the blue ones and the gray ones.... those where made in thailand and taiwan respectively..... they are not that strong but if you put good care on them they would stay to you that long...... there are black one there that really works good...... but to be so sure.... you can dismantle the rod and take a look on the terminals....
the shaft seems to be shaky a bit... but looking at the design...... that doesnt make the problem..... what im pointing at first is the terminal plates...... the dirt and stain might have reduced it capability to conduct the signal.... hope it helped..... good luck.... ill try posting mine.....