The Onken is definitely out - all milk products have lactose (milk sugars) which can't be avoided, but the Onken has added fructose (fruit sugar) - which is one of the sugars which is most easily digested, and so causes a spike of blood sugar and insulin when you eat it.
The result a.) you come out of ketosis because the body will always use the blood sugar before it uses fat b.) any sugar it doesn't use will be stored as glycogen and water, ie - fat, c.) the blood sugar rush will be followed by a low, and you will feel ravenously hungry.
As a rule of thumb - be really suspicious of any product that describes itself as "Low fat" or "Fat Free" - because they are often loaded with starches and sugars to make up for the fat removed.