Must be the time of the year!
Did mine on the A8 QS as the carpets were damp but all the drain holes were clear.
I went a slightly different method and used Instant Repair spray. This is sprayable mastic designed to repair drains, roofs and guttering, it effectively forms a sealed layer on the surface.
Looks to have worked well and been doing the watering can test on it with success.
Can be sprayed through a tube so useful for getting it into the location you want.
