The presence of an Enlightened Master is pure Cosmic Energy. The Guru Paduka puja is an offering to the sandals of the Guru or Master - symbolically an offering to the feet of the Master.
The space inside our homes is filled with ether - a subtle energy that has the property of getting contaminated by our negative thought patterns. When we air our repeated negative thought patterns like worries, fear, etc., inside our homes, the ether energy gets contaminated and remains inside in this fashion. This is the reason why we feel heavy and frustrated the moment we enter our homes. This is what causes the familiar undesirable atmosphere which grips us the moment we enter our homes.