I'm sure you're right that people do that, but that would be in contravension of both FAA and UK-CAA regulations.
Specifically 14CFR61.51(b)...
http://www.gpo.gov/fdsys/pkg/CFR-201...2-sec61-51.pdf
§ 61.51 Pilot logbooks.
(a)
Training time and aeronautical ex-
perience.
Each person must document
and record the following time in a
manner acceptable to the Adminis-
trator:
(1) Training and aeronautical experi-
ence used to meet the requirements for
a certificate, rating, or flight review of
this part.
(2) The aeronautical experience re-
quired for meeting the recent flight ex-
perience requirements of this part.
(b)
Logbook entries.
For the purposes
of meeting the requirements of para-
graph (a) of this section, each person
must enter the following information
for each flight or lesson logged:
(1) General—
(i) Date.
(ii) Total flight time or lesson time.
(iii) Location where the aircraft de-
parted and arrived, or for lessons in a
flight simulator or flight training de-
vice, the location where the lesson oc-
curred.
(iv) Type and identification of air-
craft, flight simulator, flight training
device, or aviation training device, as
appropriate.
(v) The name of a safety pilot, if re-
quired by § 91.109 of this chapter.
(2) Type of pilot experience or train-
ing—
(i) Solo.
(ii) Pilot in command.
(iii) Second in command.
(iv) Flight and ground training re-
ceived from an authorized instructor.
(v) Training received in a flight sim-
ulator, flight training device, or avia-
tion training device from an authorized
instructor.
(3) Conditions of flight—
(i) Day or night.
(ii) Actual instrument.
(iii) Simulated instrument conditions
in flight, a flight simulator, flight
training device, or aviation training
device.
(iv) Use of night vision goggles in an
aircraft in flight, in a flight simulator,
or in a flight training device.
It goes on to say that you can use it for proving minimum legal currency, but I can't see anything that says you may not.