Considerations for routing the use of Repels are ensuring that there is
always one in effect when in a place where wild encounters can occur,
avoiding the "REPEL's effect wore off" box whenever possible (by using
another Repel before then or by timing it to occur during a forced walk),
and money to buy enough of them.

3 Repels (100 steps, ¥350) are bought from the Vermilion Poké Mart
and used to get through Rock Tunnel, each being used before the last
expires so as to skip the box. The last runs out along Route 10 on the
way into Lavender.

11 Super Repels (200 steps, ¥500) are bought from the Celadon Department
Store and used as follows:

#1: Used outside Fly house, just before flying to Lavender to do the
Tower. With the new routing through 4F (and with letting the first
Channeler walk up to you, as well as walking straight up the second
column of 7F) and perfect movement, this runs out a few steps after
leaving the Celadon Pokémon Center when healing afterward.

#2: Used immediately after exiting the Celadon Pokémon Center before
getting onto the Bike to go to the Safari Zone. This is just before the
previous one runs out, skipping the box. This runs out toward the end
of Cycling Road.

#3: Used immediately upon entering the Safari Zone before getting onto
the Bike.

#4: Used when passing the item ball after the rightward turn in Area 2 of
the Safari Zone, which is a little before the previous one runs out. Must
be done a little earlier if you need to make the detour for the Carbos
in order to still skip the box. Runs out on way to, or during, Silph Co.

#5: Used immediately upon landing in Pallet after getting HM04 before
getting onto the Bike to go toward the water. Lasts until a little into
the basement of Pokémon Mansion.

#6: Used immediately upon entering the Mansion basement, skipping the
box. (If you get the Carbos, use the Super Repel then the Carbos in one
menu invocation.) Runs out on way to Celadon Gym.

#7: Used immediately upon exiting the Viridian Gym after Giovanni II
before getting onto the Bike. Lasts until a little past the water on
Route 23.

#8: Used immediately upon exiting said water before getting back onto
the Bike, skipping the box.

#9: Used before second boulder in Victory Road, skipping the box.

#10: Used in narrow passageway toward fourth boulder in Victory Road,
skipping the box. Can actually be done pretty much anywhere before that
on 3F, since the last Super Repel is used long before this one runs out.

#11: Used immediately after falling down the hole from 3F to 2F before
getting back onto the Bike, skipping the box (this is actually long
before the previous one expires). With perfect movement from there
(including using the Indigo PC and possibly using the Indigo Pokémon
Center), runs out toward the end of the automatic walk into Lance's room,
causing the box not to appear. Even with small imperfections and detours
(most notably, if you buy anything from the Indigo Poké Mart), still runs
out along that walk (it's long!), still causing the box not to appear.

If somehow short on money at the Celadon Department Store, #11 can be
skipped. The only reason it's there is for the box skip, and the only
reason this saves time is that you need to enter the menu anyway to get
back on the Bike and so can use the 11th Super Repel while in there.

(Now that I write that, is #11 even worth it at all? You're incurring
the extra button presses to buy it and use it and the "I used SUPER
REPEL!" box just to avoid a "REPEL's effect wore off" box.)