Een beetje lauwe melk is a bit of lukewarm milk (I guess a tablespoon or two) not a bottle. The dough must remain firm.
Leave the dough to rise in a warm place (not plate)

The Wafelijzer is basically two hot plates that squeeze the dough to a thin layer (one tenth of an inch) and bake it in 30 seconds. Use a knife to lift it of the plate when done, then immediately slice it in two while it is still hot and apply the hot syrup (jam might be a nice variation!) and put the slices together. Warning: let it cool off a bit, hot syrup can cause nasty burns.

Since you have to be fast when cutting and applying the syrup, it may be best to team up. More fun too.

regards, Jeroen