He hasn't had too many songs in Dutch, actually, aside from Heilig Vuur, which is entirely in Dutch. I actually think that it works well. He usually only has between 1 or 3 songs in Dutch, if any, per album. Bloed In De Sneeuw from The Return Of The Horned One (and rerecorded for the new album, which is great) is a really good song.
If you go to the Barbarian Wrath homepage, you can listen to two tracks from every Countess album except the first one, which was released independently by the band.