I have had success.

Background: Windshield sprayers were under performing, then the drivers side quit altogether.

Removed reservoir tank (removed fluid level sensor first), removed pumps (just 2 in my case), removed screen beneath the pumps and found some sort of mucous-based alien life form growing at the bottom of the tank and clogging the screens.

Cleaned inside of reservoir tank using hot water and scrubbing with some paper towels using a 18" socket extension for some 'muscle' (note: came close to vomiting but didn't). Reinstalled reservoir.

Sucked water lines clear with a Mighty-Vac. This left me with one good performing nozzle and one that was entirely clogged.

Removal of nozzle: Unplug the electrical wiring (mine goes to a nozzle de-icer), and the water line. Remove the grill that holds the nozzle (there are 8 or more tabs that need to be pushed and since I am not an octopus I found this awkward but not impossible). Remove the nozzle from the grill by pushing in tabs fore and aft on the nozzle and pushing through the grill.

I used a sewing pin and blew through the nozzle to clean. Results: all back together with two powerful window sprayers!

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2003 X5 3.0 - Original Owner