Holes with NO Support

I have been working on a method of printing fairly simple designes, with holes, WITHOUT support material.

So Far, I have had quite good results.

HOW, I hear you screeeeeemmmm !!

AS he print gets just befor the piont at which it would 'string' over a blinde hole, (as in the STL file) fill it with blu-tack,

simmilaly, as can be seen in the photo, a slug af blu-tack has been added (needs to be a bit longer).

as the print progresses to crowning point, squeese the blue tack, to fill t