How do Protestants explain the incorruptibility of Catholic and Orthodox saints?

As far as I know, there is a vast body of evidence of incorruptibility of some saints in Catholic and Orthodox Churches. Here is a picture of the incorruptible relic of St. Aleksandr Svirskij from Wikipedia : Such cases have often been presented as a proof of the correctness of the Catholic and Orthodox Faiths - as opposed to the numerous Protestant faiths (as far as I know, there are no cases of incorruptibility in Protestantism). I wonder if any attempts have even been made in the main-stream Protestantism to explain this body of evidence or was it simply ignored? If there were such attempts made, then what main points have been presented?