Yevamos 74a - Annointing is like Drinking

The Gemara says that ma'aser that is tamei can be used for anointing. Why speak about ma'aser tamei, since ma'aser tahor can also be used for anointing? Rashi says that one would of thought that ma'aser tamei can't be used for anointing since anointing is like drinking, and it would be like drinking ma'aser tamei, therefore we are taught that even ma'aser tamei may be used for anointing. Rashi understands that bec. of sicha k'shtiya, the default position would have been to assur anointing with ma'aser tamei, so we need a gezeiras hakasuv to be matir. However, Tosafos says that the chiddush of ma'aser tamei is that since there is a prohibition to benefit from the burning of ma'aser tamei (not like terumah - 73b), it should also be assur to anoint since it is like burning (consuming not through eating), so we need a gezeiras hakasuv to be matir anointing.
Tosafos does not explain like rashi since Tosafos holds (nidah 32a) that the concept of sicha k'shtiya - anointing is like drinking, is only derabonon, so we don't need a pasuk to exclude that premise. But, Rashi seems to understand that sicha k'shtiya is d'oraysa so the default would be to assur anointing m'doraysa since it is tantamount to drinking ma'aser tamei, and the pasuk comes to be mechadesh that anointing with ma'aser tamei is mutar.

See Maharatz Chiyus who raises this issue but does not turn it into a machlokes rashi and tosafos.