Rubber band technique for english stress

This technique is useless for many L2 speakers: it is like putting cart in front of the horse.

One can stretch long vowels without any difficulty; however, if L2 speakers are asked to stress short vowels as in po'sItion, they end up producing BEAT vowel. Your rubber band makes them to produce BEAT vowel.

The trick doesn't lie in vowels, dammit. It is consonants just prior to the stressed short vowels: release these consonants slowly, if stops; hold the consonant for a bit longer, if fricatives. Same trick is used in dancing: you don't dance on the beat, as you don't know what is gonna come. Just stay behind the beat!!