It is lawful and right as per the Shariah without any doubt to sprinkle the water on the walls of the house and in other places of house where none would put his feet. Yes, you should avoid sprinkling the water at a place where it is feared that one might put his/her feet. There is a dua mentioned in hadith for paying the debt, you should recite it extensively. The dua is here:
اللَّهُمَّ اكْفِنِي بِحَلَالِكَ عَنْ حَرَامِكَ وَأَغْنِنِي بِفَضْلِكَ عَمَّنْ سِوَاكَ.
In-shaAllah, soon your debt shall be paid and you shall be blessed with halal provision.
Allah (Subhana Wa Ta’ala) knows Best
Darul Uloom Deoband