You can easily transform color pictures to "cream" monochromes, but I would to have them in pure Black & White. Where can I get new effects like this?
Conversion to black and white is not a simple process. It's rather an art form. There are dozens of plug-ins for back and white conversion for LR alone, and each has dozens if not hundreds of options...
If you only want to de-saturate your image, use the Hue, Saturation and Value effect. Pull the saturation all the way to the left.