have tried everything with the same results. after the first one, another will join the song and soon the trees are full of bird song, lifting their voices in praise of god. i thought "apple" as soon as i clicked the link. also freshly squeezed orange juice and strong coffee is a must and they did not fail to deliver. but be sure you double the batch, because you will want some to scent your own home as well once you smell it! this is how i usually do this things, never had a problem. 