Xenon washer

This might be a daft question, but how does the headlamp washer operate on a 197 with xenons?

I assumed it would work when I operated the windscreen washer but it doesn't.

I've looked in the manual can't find anything there......am I missing somfink?:001_unsure:
 
Lights on, hold for longer windscreen was and they squirt one side at a time.
Only operate when the lights are on.