Using DME only is perfectly acceptable the FAA does not actually specify how exactly to execute the procedure turn but where and at what altitude. This is covered in the AIM:
5-4-9 Procedure Turn and Hold−in−lieu of Procedure Turn. A procedure turn is the maneuver prescribed when it is necessary to
reverse direction to establish the aircraft inbound on an intermediate
or final approach course. The procedure turn or hold−in−lieu−of−PT is
a required maneuver when it is depicted on the approach chart, unless
cleared byATC for a straight−in approach. Additionally, the procedure
turn or hold−in−lieu−of−PT is not permitted when the symbol “No PT” is
depicted on the initial segment being used, when a RADAR VECTOR to the
final approach course is provided, or when conducting a timed approach
from a holding fix. The altitude prescribed for the procedure turn is a
minimum altitude until the aircraft is established on the inbound
course. The maneuver must be completed within the distance specified
in the profile view. For a hold−in−lieu−of−PT, the holding pattern
direction must be flown as depicted and the specified leg
length/timing must not be exceeded.
The guidance is pretty straight forward that you need to be at the prescribed altitude and within the "remain within" distance but the type and execution of the maneuver is largely up to the PIC as they go on to elaborate.
On U.S. Government charts, a barbed arrow indicates the maneuvering
side of the outbound course on which the procedure turn is
made.Headings are provided for course reversal using the 45 degree type
procedure turn. However, the point at which the turn may be commenced
and the type and rate of turn is left to the discretion of the pilot
(limited by the charted remain within xx NM distance). Some of the
options are the 45 degree procedure turn, the racetrack pattern, the
teardrop procedure turn, or the 80 degree, 260 degree course reversal.
Racetrack entries should be conducted on the maneuvering side where
the majority of protected airspace resides. If an entry places the
pilot on the non−maneuvering side of the PT, correction to intercept
the outbound course ensures remaining within protected airspace. Some
procedure turns are specified by procedural track.These turns must be
flown exactly as depicted
The standard 1 minute timing is a convenient way to execute the maneuver for light aircraft since 1 minute at approach speed is usually ~1.5 miles (assuming a 90 Kt maneuver/approach speed) and will often keep you in the protected area.
Depending on how you read the regulation in reality a pilot may only use distance, although you may use time as an estimate and helper to execute the maneuver.