The book can be deleted from the Reader with the patch implemented in May by Shade (probably you know him as an author of the clock patch). Sorry, this post is in Russian:
http://www.the-ebook.org/forum/viewt...?p=83130#83130
I think you can easily understand how to apply the patch if you are familiar with igorsk's universal flasher (
https://www.mobileread.com/forums/showthread.php?t=10900).
Briefly:
1. It can delete book from the reader's memory if there are no collections.
2. From the book, go to Utilities, press "mark", and you will be prompted to delete the book with the "size" button.
http://ifolder.ru/2140673 - the file you need to unpack (including subfolders) to the flasher by igorsk; then follow his instructions (see
https://www.mobileread.com/forums/showthread.php?t=10900)
I'm happy user of this feature for 3 month (along with the clock, joystick and uniform fonts).
DANGEROUS HACK! DO NOT USE!