An extraordinary deviceless self-sustained oscillatory diffusive burning is observed in tert-butyl peroxybenzoate (TBPB) (technical pure) and hybrid fuel, i.e., TBPB and kerosene (both 50%) flames when burned in form of pool fires. Such oscillations or more precisely self-sustained deviceless control of mass burning (flow) is not reported till date. Generally, devices comprising electronic control system and/or mechanical means (valves) are necessary to produce such oscillatory burning or control of fuel flow. This unique oscillation is strongly recorded for pool diameters of 6 cm <= d <= 11 cm beyond which the effect was weakened and unseen (hid) visually. The fuel regression (loss) takes place in irregular time steps and is formulated in form of a step function. The variation in fuel mass burning rates, visible flame lengths and radiation heat fluxes with time are measured as respective representatives of oscillations. The periodicity in the strongest oscillations in relative visible flame lengths is investigated and the measured data are found to be best fitted in sinusoidal form. Both, chemical and thermal effects are shown to be possibly responsible for such effects. Furthermore, a theory is offered to characterise similar effect showing fuels. (C) 2013 Elsevier B.V. All rights reserved.