You must not follow Gaudiya Vaishnavism to practise pure Bhakti (even is ISKCON says that), you can worship Shiva, Devi, Ganesha,... any deity with Bhakti.
Absolutely, Cypress!
Forgive me for speaking out on this topic but I feel the impluse to add some thoughts please to this on going thread in general.
Dualism arises in nondualism. The rejection of nondualism for dualism only occurs in a dualistic mind. I strongly state that dualism or a dualistic mind is not wrong or less, nor is Bhakti, nor Gaudiya Vaishnavism nor dvaita wrong nor less, they are good and natural. As right and wrong are both dualistic, it requires another force to guide the devotee to the supreme goal through the dualist path. This force becomes more salient and noticeable during the search. This force can be called faith, ritual, intuition etc, until at such a point profound realisation occours and search flowers into delight. It does not mean action or faith or bhakti ends or is rejected, that is the misconception of nondualism I hope to clarify.
Bhakti can and does arise from nondualistic realisation. Bhakti, prapatti or service to the Lord can be both the path and the result (to taking refuge in the divine). As to what degree and when bhakti influences the spiritual path of the devotee, is down to many factors, apparently individual to the onlooker. These factors include svabhava (one's nature), karma, gunas and prasad/anugraha or grace/blessings of the Lord.
As to how these has defined the devotees direction will become clear as the realisation deepens, so to speak. The point I am trying to make is that the name changing and to-ing and throwing in the seeker that occours is natural. No sooner does one feel they are on the right path then a factor comes along to indicate the path is in fact wrong. Keep the focus and use the energy to broaden us. Lets not be discouraged my friends. Rather lets wish for success and clarity in the next fascianting twist on our spiritual journey. May we all merge in inner-peace and divine bliss!