If Ravi has true faith he should not have asked such questions? In mythology and Rituals there is no logic and question mark.. you just believe it and simply follow the tradition. If his priority is to please the God and present valuable offerings that can be done from the outside the temple.... Like KJ Yesudas and Gyani Zail Singh did.
I used to Visit Guruvayur and put my offerings outside, chant mantra from outside.......though I am a Hindu... simply because not to make overcrowd inside. Last but least Guruvayurappan has no shortsight
In West Bengal there is tradion of bringing clay from the land of prostitutes before Durga Puja, there is a tradition nobody argue on that. The persons like Ravi may argue why not the clay from his house?