Currently Spices.Obfuscator v5.3 obfuscates resource names, protect them from decompilation and tampering, but we're preparing solution to additionally compress and encrypt resources. Spices.Obfuscator can't completely hide resources because of wide range of ways of usage managed resources, there is no universal solution to hide resource.
But you can hide managed resource manually by using code from How to's\\How to hide managed resource in exe/dll topic of Spices.Net manual.