Friday is indeed regarded as an unlucky day by Christians because it was the day Jesus was crucified (in the same vein, there were 13 people present at the last supper and the 13th person betrayed Jesus). Whether or not friday is or was considered unlucky in non-christian cultures I don’t know.
Infants may not have been kept in barrels, but they might as well have been. The practice of swaddling was worse than putting children in a nice, roomy barrel.
In some books, I have read that due to the time-consuming nature of removing and changing the swaddling, children were sometimes hung on pegs above pans to catch the “drippings.” Sometimes, according to these sources, the swaddling was not changed for days. The diaper rash must have been truly a sight to behold.