I assume you are skipping insulin so that your sugars rise, so that you go into ketosis - which would cause you to drop weight rapidly (i lost 30lbs in 3 months before my diagnosis).
This is a VERY bad idea.
I have seen numerous websites stating that organ and cell damage occur when blood sugars rise above 7.8mmol/L. I do not know the extent of the damage it would cause but every time day you allow your BS to rise above that mark you are certainly shortening your life, and potentially causing kidney, heart, nerve or eye damage :/
Sure, you'll lose weight now, but as soon as you get back on insulin you'll likely put it all back on unless you change your lifestyle.
The best thing you can do for weight lose is count calories, eat less then you burn each day and you will loose weight, there is no reason to bring your blood sugars to a dangerous level. You can maintain them in the normal range while on a diet anyway so why risk it ?
This may seem effective, but from experience you'll put all that weight right back on, and its not a sustainable lifestyle, it will almost certainly end poorly.