4 tablespoons of bleach is way too much.
The no rinse cleaner sold at brewer supply stores works well.
Always use cold water.
There is no way to clean the drinking tube unless you get the kit.
You can probably kill the beer taste by filling partially with water and putting lemon juice in the bladder.
A teaspoon of bleach will also clean and disinfect. Rinse several times with cold water.