Cleaning a clogged espresso machine Portafilter
I alone on the planet seem to have solved the endless problem of cleaning the fine holes of an espresso portafilter, or a Moka express fine steam filter.  None of the liquid or abrasive cleaning apps work, period.  Instead, in the past, one had to use a pin to poke out the minute holes — task so laborious and hopeless than most espresso and Moka machines in the world are hampered by limited filtration.

No longer.  The pin-holes are plugged with coffee fibre, which burns.  Place the filter over a gas flame, either side, for 10 minutes, tapping it with tongs occasionally, and bingo... 
A CLEAN FILTER.  All the minute coffee fibre plugs burn or pop out.  Best to use a small coffee pot rack on top of your smallest hob gas burner for this.  And metal tongs.

Will I be knighted for this?