I believe this to be very bad advice because:

1) If the battery starts to feel warm at C/10 it could already very overcharged (if the battery is partially charged to start with) by the time you check or depending on capacity/internal resistance the battery could get warm 1/2 way through the charging process.

We aren't baking a cake here, you know.

2) Nimh have much poorer overcharge absorption than Nicad and will be damaged if trickle charged at more than 0.05C. The Nimh simply can't absorb the extra power after they reach peak saturation.

3) Slow charges cause crystalline formation (memory).

While these are all bad things - Nimh do not like being trickle charged - I believe cheap fast chargers are more damaging.

If you don't mind having batteries that are always overcharged or undercharged and have greatly shortened life expectancy (hundreds of cycles less), use a cheap charger.