Process Explorer uses VT to check files that exist on a disk. However, processes running in memory may have a malicious code injected which cannot be detected using PE or VT.
I agree with Marcos. Today's malware is fairly sophisticated. Many run at boot time, inject a process, and then shut themselves down to avoid detection. A better way to use Process Explorer is to examine the details of running processes. That will at least possibly show you any disk based malware components. Also make sure you show the "verified" column in PE view options. Also note that there is malware in existence that can totally hide its code injection. Finally, this is no substitute for AV protection whose purpose is to prevent the malware from being installed in the first place.
Strangely enough I never felt the need to use this feature , but it does look kinda cool on the video. Is there any risk involved with sending this info to VT?
I been doing this already ever since Windows 98 for crying out loud, only manually because there were no upload features directly to VirusTotal or other but trusted the AV Vendors scanning such as Kaspersky etc. In agreement that malware is so much more miniaturized and more clever than ever before.