You forgot to write for all folk that you are using iGrid in MS Access VBA :)
Not all iGrid methods and properties you can see in the Object Browser or IntelliSense are implemented directly in iGrid - some of them are provided by the host environment (they are also known as ambient properties). For instance, if you drop an instance of iGrid onto a VB6 form, you'll find the WhatsThisHelpID property among all available properties. But this property isn't implemented inside iGrid OCX, it is provided by VB6 and the probability you'll find this property in other dev envs is very close to zero.
In fact, I've already answered the question: the Requery method you'll find is a specific method provided by MS Access VBA and sure there is no help topic for it in the iGrid CHM file.