The ancient tradition of blessing the home is now completely lost. My grandmother told me about it when I was a child, and those to whom she advised to do so, were amazed.
Remember, when the priest sprinkles the apartment with water, he immediately puts the sticker with crosses on the doors and windows (putting a seal). In old days, they used to mark the house by scratching or painting crosses with oil. I mean the time when religious organization did not use stickers.
Well, religions borrowed traditions of each country where they had established. And the crosses over the windows and doors originate from the oldest ritual of blessing the house.
And it was performed as following: the oldest person in the house took milk (cow’s or goat’s), dip his index finger in it, and mark the house reciting the following:
«Good milk, save the most precious here and keep safe my family and this blessed house. As said is done!»
Then using this milk they marked the windows and doors with the symbol of… What symbol do you think they depicted? It was the symbol of the Sun!
Blessings to you and joy.