Obstructions/blockages occur over a long time frame....sodium chromate turns to crystals when overheated. It then plates out on the inside of tubes which causes more restriction to flow, more overheating, more crystals, more plating out....accumulative until DEATH and the crystals are permanent. They do NOT go back into solution, They do NOT disappear, no away.
All the flipping, bouncing, vibrating, laying on sides, upside down etc will NOT change it.....might dislodge a bit and allow some increased flow but that is just a band-aid attempt at stopping the hemorrhage.
Might seem OK for awhile but will stop working and usually at the most inconvenient time