I trained my 5 month old puppy using an Acme whistle and she responded really well to it. Then she got confident and started disappearing off into the woods and eventually came back after several whistles. Since then I stopped using the whistle and she’s back on the lead. She’s now 7 months and I want to start recall again - I’ve read a great training programme but is the whistle now associated with not obeying it or can I still use it, just maybe change the number of pips! Anyone help?!