tell U what i did.. i cut a 2 ltr bottle in half.. fliped the top side with the cap upside down. then stuck the top half into the bottom half so it would hold it.. then i pour my butter into that and let it cool. when its done cooling all the butter forms on the top and all the water is under it.. then i just unscrew the cap and let all the water drain out. pop out tha butter and put it in the fridge.. works pretty good.
I use cheapy ice cube trays from the dollar store. When the butter is melted, I scoop out 1 TBSP full and dump it in the tray. After they are cooled, I wrap them in squares of wax paper, then into the vacuum sealer for freezing.