not sure if this is because of the texture pack, but there are unsprayable patches of goop on sirena 6 making it impossible to complete
Hi! This is an issue with Dolphin's emulation, and has not been fixed yet. The best way to get around the issue is to use this simple cheat code (AR Code) to instantly complete the level:
Instant Scrubbing Sirena Beach Completion
Please note that this code is for the north american version only, which is the recommended version. An alternative method to complete the level, or if you're using the European release, set the following settings to this;
Anisotropic Filtering above 1x or Anti-Aliasing set to SSAA
Texture Cache Accuracy is set to safe
Scaled EFB Copy is disabled.