Step 1: The Problem: 50+ letters to send
In addition I had to to put not adhesive stamps on every letter. I had adhesive stamps but they were valid only for standard letters and mine got heavy so I had to put some extra postage on. And those extra postage stamps had also to be moistened to become adhesive.
So I came up with this little helper made entirely form household materials: A small peace of sponge squeezed into a clothespin.
The sponge will hold the water for moistening and the clothespin will act as a shaft to hold it without getting wet fingers (and therefor spoiling the envelopes).