I say, and with God's success: It is not sufficient for him instead of tayammum, even if he wipes his face and hands with it; because it is a condition for the validity of tayammum that it be done with three fingers or more if he wipes with his hand, and he must wipe with more than that, the minimum being three fingers. This is unlike if he rolled in the dust with the intention of tayammum and the dust touched his face and hands, for that would suffice him. It was narrated from Abdur-Rahman ibn Abzi : "A man came to Umar  and said: I have become impure and I did not find water? Umar said: Do not pray. Then Ammar said: Do you not remember, O Commander of the Faithful, when you and I were in a military expedition and we became impure and did not find water? You did not pray, but I rolled in the dust and prayed. The Prophet  said: It would have been sufficient for you to strike the ground with your hands, then blow, and then wipe your face and hands with them," in Sahih Muslim 1: 280, and Sahih Bukhari 1: 129. See: Al-Hadiyah Al-Alaiyah p. 35, and God knows best.