These ones sound like they fit the description better. The other ones I showed a pic of are the kind I was talking about that kind of 'flip' to lock.
If you've got the flat kind, it might be worth looking at this guide which has this description further down the page;
" ^The guy rope goes through the two holes as shown in the left hand picture. Note that the 'tent' cord comes out on the same side of the toggle as the 'peg' cord. This is critical. In practice this gives about one and a half turns of distributed friction.
In use, the loop at the end of the 'peg' end is hooked over the peg in the ground and the 'free' end is pulled to tighten the guy rope. It may help to pull the guy rope anchor point on the tent out by hand a bit while doing this, to minimise tension on the toggle. When the guy rope is tight enough the 'free' end is 'wound around the toggle': it is passed between the toggle and the 'tent' cord and then between the toggle and the 'peg' cord. A single turn around the toggle is shown in the right hand picture. The tension in the guy rope will pull the 'tent' cord and the 'peg' cords against the toggle, and this will grab the 'free' end where it goes between those cords and the toggle. This puts an initial holding force in the 'free' end.
This initial holding force is quite low, so by itself it can impart only a low initial tension to the guy rope. However, this low initial holding force is then multiplied up by the distributed friction in the wrap around the two holes in the toggle, in the standard 'rope around a bollard' manner. The multiplying factor is a function of the total angle of wrap, which is about 1.5 revolutions here. This is a fair bit of wrap, and the multiplication factor is high. It should also be noted that as the tension in the guy rope goes up, so does the force between the 'tent' end and the toggle (ditto for the 'peg' end'). In a way, the arrangement increases its own holding power as the load increases.^ "