Talk to yourselves, you silly and incompetent people who weren't born qualified pilots. Ignore your silly national procedures.
Don't you know that these selfish radio calls sometimes wake up real pilots who have to catch up with their sleep on long commercial sectors? That is very inconsiderate and annoying, especially if the volume is set too loud. There is nothing so tedious as reaching out to switch off the alarm clock.
Actually, I've not heard a single practice call on 121.5 in the last 3 weeks, but quite a few on other in-use ATC frequencies, which hassled a busy ATCO on one occasion.