hi,
i've tried it but couldn't get it to look like woodgrain on large areas.i like it for small areas like spade handles etc but i've gone to oils for large area woodgrain effect...with a vallejo base colour.
i use a base colour of vallejo model colour - natural wood 70834(let that dry),
then i use mig/abteilung oil wash brown 080 , mixed with windsor and newton - liquin original, a drying agent.
brush it on and leave it for half an hour then go back and do your grain pattern.
i do really like the vallejo paints but i personally think that oils are best for woodgrain.
paul